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151.
The effects of training overhand ball throws to enhance underhand ball-throwing accuracy were studied with 921 Italian high school pupils (575 girls, M age = 16.5 yr., SD = 1.3; 346 boys, M = 16.5 yr., SD = 1.2) ages 14 to 18 years. A standardized test (10 underhand tennis-ball throws into the floor area delimited by an 80-cm radius wooden hoop lying on the floor 9 m from the standing pupil) was performed and scored. An Experimental group (435 girls, M age = 16.5 yr., SD = 1.3; 204 boys, M age = 16.5 yr., SD = 1.2) was randomly selected to participate in 10 weekly training periods. The set included 10 overhand throws of a rubber bouncing ball (14.5 cm diameter, weight 240 g) into a basketball hoop from 5 standardized positions (in front of the basketball hoop; at 45 degrees, 90 degrees on the right and on the left of the basketball hoop) at a distance of 4.40 m. The underhand test was repeated for both groups. On the average, boys obtained higher test scores than girls of the same age. Older adolescents had higher mean scores than younger adolescents. After 10 weeks, boys and girls of all ages improved. Mean differences between sessions were significant for the Experimental group (Student t test, p < .01). In Session 2, consistent differences between Experimental and Control groups were also found (Student t test, p < .05).  相似文献   
152.
What are the benefits of negative thinking and negative affect? Although previous studies in evolutionary psychology, social psychology, and clinical psychology have clarified the question, there has been no definitive study asking people directly about the perceived benefits. In the present study, 119 Japanese undergraduates were asked how they recognized the benefits of negative thinking and negative affect. Their answers were analyzed qualitatively. The answers were arranged into 30 smaller categories and 12 superordinate ones. The benefits were divided into "benefits to the self" and "benefits to interpersonal relations". Finally, the conditions necessary for the negative thinking and negative affect being benign, and possible cultural differences, were discussed.  相似文献   
153.
Effects of audience awareness on procedural text writing   总被引:1,自引:0,他引:1  
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154.
The short scale of the Eysenck Personality Questionnaire-Revised (EPQR-S; H. J. Eysenck & S. B. G. Eysenck, 1992) is a 48-item personality questionnaire primarily designed to measure an individual's level of extraversion (vs. introversion) and neuroticism. Although L. J. Francis, L. B. Brown, and R. Philipchalk (1992) created the Eysenck Personality Questionnaire Revised-Abbreviated (EPQR-A), an even briefer version of the EPQR-S, the reliability coefficients of some of the measures have been less than satisfactory (S. Forrest, C. A. Lewis, & M. Shevlin, 2000). Because brevity and reliability are both extremely important, the author of the present study created a briefer version of the EPQR-S, more reliable than the EPQR-A, by making slight alterations in the item content as well as the response format of the EPQR-S. Two hundred and sixty eight participants completed the original EPQR-S and the 24-item newly revised briefer version of the EPQR-S (EPQ-BV) twice. The findings revealed that the EPQ-BV has good internal consistency, test-retest reliability, and concurrent validity. A principal component analysis revealed a solution with factor loadings that accurately reflected the primary measures of the EPQR-S. These findings are discussed in relation to the psychometric properties of the EPQR-A and the original version of the EPQR-S.  相似文献   
155.
Metallic glasses exhibit low viscosity in a temperature range between the glass transition and the crystallization temperature, a feature that allows successful sintering of glassy powders. Microwave heating, being volumetric, has significant advantages over conventional heating in materials processing, such as substantial energy savings, high heating rates and process cleanliness. In the present study, we investigate the stability of Cu50Zr45Al5 glassy powders and the formation of a bulk two-component metallic glassy-crystal sample by microwave heating in a single-mode cavity (915 MHz) in an alternating magnetic field.  相似文献   
156.
Helium generated in materials by the nuclear reaction (n,?α) is generally considered to be harmful. It is well-known that helium prompts not only the nucleation of interstitial-type dislocation loops, but also the nucleation of voids in metals and alloys irradiated with high-energy particles, which degrades their mechanical properties. In this study, however, we find that helium trapped by dislocations in Ni increases both the ultimate tensile strength and total elongation.  相似文献   
157.
A series of tensile and microbend tests were conducted on aluminium single-crystal foil specimens with different thicknesses ranging from 20 to 90?µm. Two different crystal orientations relative to the tensile direction were considered in the tests: one is an orientation that was excepted to activate at least four slip systems on four different slip planes, and the other is an orientation that was expected to activate only a single-slip system. In the tensile tests, typical size dependence of initial yield strength was observed. The microbend test method was extended to include a reversal of bending direction. Using the curves of bending moment normalized by the square of foil thickness versus surface strain, which were obtained from the reversed bending tests, the total amounts of strain hardening were divided into isotropic and kinematic hardening components. In the microbend tests, a pronounced size-dependent kinematic hardening behaviour was clearly observed; meanwhile, the amounts of isotropic hardening were very small, particularly for the single-slip orientation.  相似文献   
158.
He and H can be produced by nuclear reaction. In addition, energetic particles of He and T and D, which are isotopes of H, in the plasma of fusion reactor induce the damage in the surface of materials, such as erosion, sputtering and blistering. To investigate the interaction of He and D, amorphous and crystalline FeBSi alloys were irradiated by He or D2 or He?+?D2 ions with 5?keV. The results of thermal desorption indicated that more He atoms were trapped in both the amorphous and crystalline alloy irradiated by He ions than D atoms in those alloys irradiated by D2 ions. Although He and D atoms were trapped in FeBSi alloy irradiated by He?+?D2 ions, desorption peaks of D2 and He were separated. Absorption of D in an amorphous alloy was influenced by the presence of He; however, absorption of He was independent of D2 irradiation in both alloys.  相似文献   
159.
Amnesia is the main phenomenon in dissociative experiences. The present study investigated whether amnesia in participants with frequent dissociative experiences depended on state-dependent memory. Undergraduates scoring high (n=32) or low (n=32) on the Dissociative Experiences Scale Version-II (DES-II) participated in this experiment. Mood induction and a remember/know task were used in a typical mood-independent memory design. In the inconsistent mood state condition, participants in the high DES group showed decreased memory performance compared to the low DES group. These results were attributed to the recollection components of recognition and not to the familiarity component. Therefore we concluded that the normal population with highly frequent dissociative experiences showed strong state-dependent memory and had a memory bias in the recollection component of memory.  相似文献   
160.
Gravity reduction affects the energetics and natural speed of walking and running. But, it is less clear how segmental coordination is altered. Various devices have been developed in the past to study locomotion in simulated reduced gravity. However, most of these devices unload only the body center of mass. The authors reduced the effective gravity acting on the stance or swing leg to 0.16g using different simulators. Locomotion under these conditions was associated with a reduction in the foot velocity and significant changes in angular motion. Moreover, when simulated reduced gravity directly affected the swing limb, it resulted in significantly slower swing and longer foot excursions, suggesting an important role of the swing phase dynamics in shaping locomotor patterns.  相似文献   
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